Estimating Methane Emissions From Underground Coal and Natural Gas Production in Southwestern Pennsylvania Geophysical Research Letters

Production of coal and natural gas is responsible for one third of anthropogenic methane (CH4) emissions in the United States. Here we examine CH4 emissions from coal and natural gas production in southwestern Pennsylvania. Using a top-down methodology combining measurements of CH4 and ethane, we conclude that while Environmental Protection Agency inventories appear to report emissions from coal accurately, emissions from unconventional natural gas are underreported in the region by a factor of 5 (+/- 3). However, production-scaled CH4 emissions from unconventional gas production in the Marcellus remain small compared to other basins due to its large production per well. After normalizing emissions by energy produced, total greenhouse gas emissions from Pennsylvania unconventional natural gas production produce half the carbon footprint compared to regionally produced coal, with carbon dioxide emissions from combustion being the dominant source of greenhouse gas emissions for both sources.

美国人为活动产生的甲烷（CH₄）排放中，约三分之一源自煤炭与天然气的生产活动。本研究针对宾夕法尼亚州西南部地区煤炭及天然气生产过程中的甲烷排放展开分析。我们采用结合甲烷与乙烷检测的自上而下研究方法，得出结论：尽管美国环境保护署（Environmental Protection Agency, EPA）的排放清单对该区域煤炭行业的甲烷排放统计较为准确，但非常规天然气的排放数据被低估了5倍（误差范围±3）。不过，由于马塞勒斯（Marcellus）页岩气区单井产量较高，按生产规模折算的非常规天然气甲烷排放总量仍低于其他多数盆地。以单位能源产出为基准对排放量进行归一化处理后，宾夕法尼亚州非常规天然气生产的总温室气体排放碳足迹仅为区域内生产煤炭的一半；且两类能源的温室气体排放主要均来自燃烧过程产生的二氧化碳排放。